Photocatalytic H Evolution on TiO Assembled with TiC MXene and Metallic 1T-WS as Co-catalysts.

The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst's surface. In this paper, we report that double metallic co-catalysts TiC MXene and metallic octahedral (1T) phase tungsten disulfide (WS) act pathways transferring photoexcited electrons in assisting the photocatalytic H evolution. TiO nanosheets were in situ grown on highly conductive TiC MXenes and 1T-WS nanoparticles were then uniformly distributed on TiO@TiC composite. Thus, a distinctive 1T-WS@TiO@TiC composite with double metallic co-catalysts was achieved, and the content of 1T phase reaches 73%. The photocatalytic H evolution performance of 1T-WS@TiO@TiC composite with an optimized 15 wt% WS ratio is nearly 50 times higher than that of TiO nanosheets because of conductive TiC MXene and 1T-WS resulting in the increase of electron transfer efficiency. Besides, the 1T-WS on the surface of TiO@TiC composite enhances the Brunauer-Emmett-Teller surface area and boosts the density of active site.